BatChat

Sue Swift & friends at the Scottish Bat Conference

December 23, 2020 Bat Conservation Trust Season 2 Episode 18
BatChat
Sue Swift & friends at the Scottish Bat Conference
Show Notes Transcript

S2E18 In November 2019 before the word Coronavirus had become all-too familiar, the Scottish Bat Conference was taking place in Perth. In this episode Steve speaks to Liz Ferrell BCT's Scottish bat officer, Sue Swift who published the authoritative work on long-eared bats and Tracey Jolliffe who has an interest in zoonotic diseases and discusses bats and rabies. 

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Steve Roe:

Hello, and welcome to BatChat the podcast from the Bat Conservation Trust where we're talking to both experts and local heroes to bring you the stories from the bat conservation movement. Thanks for downloading this week's episode. We hope you enjoy it. I'm Steve Roe, and we're halfway through this series of BatChat. Now, last year before we even heard of the word Coronavirus, the world was a very different place with conferences taking place in person, and people enjoying networking with each other to learn about the latest studies and conservation work being done with our bat species. One such Conference which takes place each year is the Scottish Bat Conference, which last took place in Perth last November. And in this episode, we have three guests from that event. On the day of the conference, I spoke with Sue swift who wrote the infamous monograph on long-eared bats, which despite being published in 1998, is still in high demand. And with Tracy Jolliffe, who is a rehabber of poorly bats, but also has a keen interest in zoonotic and anthropogenic infections. But before that, on the eve of the conference, I caught up with the Bat Conservation Trust's Scottish bat officer, Liz Ferrell, who had been spending the afternoon getting things ready in the Conference Centre, ready for the following day. So it's the day before the Scottish bat conference, and I'm sat in a bar relaxing with the Scottish bat officer and a load of other BCT staff. Liz, how long have you been the Scottish bat officer for BCT?

Liz Ferrell:

It seems like I've been Scottish officer too long in a bar! So it sounds a bit wrong here. No, it's all aboveboard! And I've been the Scottish officer for over just over two years now. So started in July 2017.

Steve Roe:

What was your job background? What were you doing before this?

Liz Ferrell:

So I did a degree at University of Glasgow zoology degree and after that I worked for the Scottish wildlife trust for for six months. And I then did a bit of consultancy. So that was for a year. And and that was my short history before BCT.

Unknown:

And why that's what was it the major move away from all that stuff and move into that.

Liz Ferrell:

There's just hasn't really, I mean, I love all wildlife. But when I was on holiday in Wales, and I saw a roost emergence, pipistrelle roost emergence, I've just never really felt like that before when I've watched well, but if they were just sweeping right above my head, and I just thought, well, they're really quite magical. And intriguing. And I just instantly then wanted to learn more about them. And yeah, it's just making I've just got this fascination with them. They're so intriguing, and there's so much still to learn. It's just Yeah.

Unknown:

What does the BCTs Scottish bat officer do what you get involved with job wise?

Liz Ferrell:

Oh, goodness, it's, it's very wide ranging. So for people that maybe don't know, I'm the only employee based based in Scotland. So as a wide ranging role, I help support the Scottish back groups to volunteer groups here in Scotland, whether that be with their own individual projects, whether that be training, for instance, delivering a Scottish conference. And another, the mean, other part of my role is then working with closely with the National about wanting programme, team down in down in London, and delivering, delivering that up here. So again, giving training to volunteers, so they can undertake the service.

Steve Roe:

And you mentioned Scottish bat groups there. How many bat groups are there in Scotland?

Liz Ferrell:

So I know, this is one that's just gone into hibernation, unfortunately, but I'm sure they will kickstart at some point in the future. So I think in the moment now got 11 active active troops,

Steve Roe:

and why does BCT put these regional conferences on?

Liz Ferrell:

I there's I mean, there's a variety reasons, but the main one is to have some sort of event where that workers can come together, you know, particularly in Scotland, you know, we're back workers are so spread apart. And it's just nice to have one event in the year where we can kind of all come together, catch up. But also, you know, learn something about bats. And certainly I've already learned a few things. Ahead of the conference tomorrow, obviously, I've had a look at few of the presentation slides already cheekily. And I've already learned some new things. So yeah, I think it's just bringing people together and actually just sharing some updates on that as well.

Steve Roe:

So how many bat workers from Scotland will come to tomorrow's conference,

Liz Ferrell:

we have 115 booked on, and that is pretty typical. What's nice. That's a good a good number to have altogether

Steve Roe:

and how much work goes into organising a conference like this.

Liz Ferrell:

So I am quite particular, I did keep a really good time she actually so I can tell you exactly. It's 24 days of my time. And obviously that is spread across quite a few months. So a lot of work. So yeah, it's quite a chunk chunk of my work here. And obviously,

Steve Roe:

we'll be hearing more tomorrow, but is there much of that research taking place in Scotland? Because most of its, you know, upland areas, Highland areas like that. It's quite sparse, barren landscape.

Liz Ferrell:

Yeah. And, you know, if you'd asked me kind of two months ago with, oh, you know, this, this, so many so many gaps, we're actually going to dig in to areas well actually find that there has been work done. It's just, you know, the data storage and actually knowing what has been done, that can be the tricky bit, but know what I mean, is the thing with the area being so remote population levels being low, there is there is lots of gaps across the highlands, but not not just the highlands, you know, other areas as well in Scotland.

Steve Roe:

And a big feature of Scotland, obviously, or the islands on the north and the Western coasts. What about those islands of those ones that have been surveyed? Are the bats there? Or do we really not know that much about them?

Liz Ferrell:

Yes. So again, if you'd asked me a year ago, I would have been like, ah, there's been nothing done. And I've actually spent a bit of time this summer, going to some islands. And Isla as an example. polisi had done some work on the island before found, found out that he'd monitored a natural interest on the island. And actually, humans really, really great for bats from what I can tell so far. And some of them have as many as six species. In him obviously, the more far flung ones, it says the Hardy common pipistrelle, but But no, there's quite a bit of diversity on there.

Steve Roe:

So presumably, if people are coming to Scotland on holiday, would it be useful to get their records from them?

Liz Ferrell:

Definitely. Yes. You know, we want long term trends. So repeat sites over and over. That is really important data, but the more ad hoc information is still really useful for us. So yeah, definitely, you know, get get recording.

Steve Roe:

And how many bat species are present in Scotland?

Liz Ferrell:

So I always say 10. Brandt's is the question mark one. There was a single bad dropping sent off for DNA analysis from Galloway forest. And it came back as Brandt's. So let's, let's see, optimistic. Maybe we just need to do a bit more work and then find out.

Steve Roe:

Are there any unusual roosts that are known from Scotland? And if then that stands out?

Liz Ferrell:

Well goodness. There was a few I guess, aliens

Steve Roe:

And if there are Scottish residents, listening to again. You know, that's just a personal interest and being the one on Isla is interesting. Natterer's roosting. From the photo I've seen, it's our it's our sizable roost. 50 plus would be the individuals and then I look at the habitat rain the boat, and I think, oh, it looks quite bad. And it's quite open. I think goodness, how does the How did they actually survive. And in doing some real tracking work we've seen also in 2000, that's in in a gallery, someone's house, and they've moved out of their own bedroom, because they liked the bat so much. And think, Wow, that was an incredible risk to visit. You this, who would like to get involved in that conservation or did lose count on that one. come along to an event to see what it's all about? Where's the best place for them to go and get more information about that?

Liz Ferrell:

Certainly, you know, just look locally at your kind of events, pages, so many activities happening, but what's happening and whether it is a bat group or or you know, it could be your Scottish wildlife trust, RSPB. There's bound to be something done locally. And we certainly keep a lot of information on our website as well as events that we're aware of. But certainly first first step is step in to see there's a local back group in your area.

Steve Roe:

Cool. Good luck for tomorrow.

Liz Ferrell:

Oh, thankyou. Thanks.

Steve Roe:

So it's the following day, and the Scottish conference is well underway. Now we're in the first coffee break, and I've managed to grab a few minutes with Sue Swift and Sue is probably best known for publishing her monograph on long-eared bats, which was published back in 1997. So what has your career with bats been, where have you worked, what have you been built been involved with over your time as a bat worker?

Sue Swift:

Seem to have been at it forever actually, started back as an undergraduate in 1976 in Aberdeen, when Paul Racey was just getting bat ecology established. I did an undergrad project with him and then we followed that up with the first major field study of ecology and behaviour of bats in Scotland and that took us three years. We followed that up. First. I followed that up 30 years as a research fellow on and off in the University of Aberdeen. After the initial study really went on to more conservation biology type things I did the first study really on the effects of timber treatment chemicals in in bats, we were able to show how damaging things like Lindane were, and were instrumental in getting chemicals based on permethrin to replace them. After that, it did a very, very variation of projects. My favourite one was on how gleaning that so I've always been fascinated by gleaning bats and how they work. Working with a German colleague, we did a project on how these gleaning bats perceive their prey, how they capture their prey, and how their echolocation structure matches with their morphology to allow them to clean. It was [an] absolutely amazing project and also enabled me to keep keep little colonies of Natterer's and brown long-eared bats in a field of flight room, which I found utterly fascinating, was alive beginning of a lifelong love affair with these bats. I've also worked on a project to design and build heated bat houses as mitigations for replacing lost pipistrelle roosts. And my latter part of my research career was on sampling and testing bats for EBLV viruses in Scotland, which took us eight years as a major project sponsored by SNH. At the same time as all this, I was doing consultancy, part time, I was one of the first consultants in Scotland. And I did that full time from about 2010. until I retired two years ago, I found some very interesting projects in that too. So it's been an amazing life with thatQ

Steve Roe:

So only a small amount of things. In 2009, you were the first woman to receive the Pete Guest award how did that feel? And how do you think the gender balance in bat workers has been restored now?

Unknown:

Well, the first thing was, I was very surprised to win it. And I was also very honoured to win it. It didn't actually occur to me at the time that I was the first woman to win it. I was kind of used to being one of the very few women in bats and research. But yes, the gender balance has undoubtedly been restored women more than hold their own in Bat Conservation at the moment. And we have a very, very worthy winner this year. So yes, I think the answer is they definitely has. Yeah.

Steve Roe:

And what was it that made you write the monograph for the long-eared bats where to come out of?

Unknown:

There was a colleague actually, who was asked to write one on pipistrelles and for some reason, turned it down but said, Oh, if you want a good one on brown long-eared bats just go and ask Sue Swift. So I was sort of trapped into doing it. At the time, I had a lot of other things in my life and didn't realise how long that book would take. But I'm really glad I did it in that it pulled together all the research at the time, it was fascinating to write. And it was an achievement.

Steve Roe:

And it's something that's still referred to now. I mean, I've got a copy of myself and I still refer to it even now.

Unknown:

I read it actually before this podcast. And it still holds up remarkably well. So yes, I'm quite proud of that.

Steve Roe:

And just in a bit of a crash course, which I know is difficult in the time we've got but can you just tell us a bit more about the ecology of long-eared

Unknown:

well, I've written down just a few things because as I say that you could spend a lifetime on this. They're small bats, they're in case of brown long-eared bats, they're relatively common and widespread in Britain. They live in houses. They're one of the most recognisable species and the best known to the public. They live in small colonies. They fly slowly. They have huge ears, they forage by gleaning mainly in Woodland, they use their big ears to listen for prey sounds they echolocate very quietly, which makes it difficult to pick them up on bat detectors. They meet an autumn and winter they hibernate in trees, buildings and caves. They produce one young a year and the young learn to fly in the roost. Although our two British species are very similar to look at. They have noticeable differences in their ecology and behaviour which makes them fascinating to learn. They also do this speciation there's lots of different now, the more we see of genetic genetics, more we realise how many different species of long IDs there are, which is another story altogether, but fascinating.

Steve Roe:

And you've mentioned gleaning a couple of times now just for listeners at home who don't know what that is can you just quickly explain that for

Unknown:

Gleaning is taking prey at rest from surfaces rather than catching it areally so they could be crawling along the ground and picking it up or hovering above trees and picking it up or foraging right in among the bushes and just grabbing insects off the vegetation. You need to be able to fly slow You need to do it obviously. And you need to be able to detect the prey, which is the really interesting thing.

Steve Roe:

And that's why they've got such wide wing membranes, isn't it so they can slow they

Unknown:

They have low wing loading, and they can hover and they fly very slowly, which you can only do if you've got very broad wings.

Steve Roe:

And something that's quite typical of finding long-eared roosts is finding evidence of their feed in purchase. What must species is so big to longest need to hang up and eat it?

Unknown:

Well, I was actually thinking about that. And it when you're an eight gram bat, most moth species are quite big, your average Noctuid mouth, which is what a lot of the ones we get certainly up here, weighs between 100 and 150. milligrammes now that 22 gramme bat is roughly equivalent to you having to at full pelt, catch a live chicken, catch it, kill it and eat it, that's not surprising they use, they use these also must tend to be quite physically big, therefore they need their funds to, to, to process it to manipulate it to get the the nasty, chewy bits off, which is why they use things that they're not, they're not all moths by any means. I mean, you tend to notice things like large yellow underwings, because they tend to be in heaps. But in fact, if you look in under a perch, you'll find a lot of other things I found remains of a lot of things like small chafer beetles, which they trim the the lighter and the legs off, even large Lacewings and variety of other moths as well. So they they take quite an old, probably most of their larger prey to these little purchase, which are often in a porch or a barn or something somewhere they can get in easily. And they also use them to have a little rest and a groom and maybe, you know, just think what they're doing.

Steve Roe:

The wings that we're seeing only those that are taken back to the to the feeding perch. Presumably they're eaten a whole range of other species as well that we don't get to see

Unknown:

Exactly early studies way back in the 20s. Dietary studies on these bats were entirely done through feeding perches, which led to the sort of the myth if you like that they are totally moth specialists. But in fact, once we started doing faecal analysis on them, we find they eat a large range of insects, they tend to eat about 40% marks brown long-eareds, but they also eat a wide variety of things, flies, craneflies, earwigs spiders and opilio nice things like that. So yes, which you don't get under the the the perches.

Steve Roe:

And you said in your book, it would seem logical to assume that brown long-eareds are brown and grey long-eared's are grey but it's not that simple it is? ≈

Unknown:

No it's never that simple is it brown, young brown long-eared's have a sooty grey colour and they stay grey for about a year. And there's a huge variation in it. So telling one from the other is really quite quite a problem. But there are there are factors you can use and the experts on grey long-eared's tell me that the best ways to do it is not to look at the hair colour, but to look at the banding along the hair. So you blow gently on the dorsal fur of the back of the bat. And the grey long-eareds tend to be universally dark grey, okay, whereas the brown long-eareds have sort of stripy zones, pale zone and then a darker one and then a pale one that's a good way to tell them. Face colour is much more reliable than hair colour. So if it's if your bats got a dark brown, almost black face, it's probably a gey long-eared if it's got a brownie pink face, it's a it's a brown long-eared. Tragus shape is very distinctive. Whereas it's long and thin in the brown long-eared, it's straight in the front and then with a distinct convex loop and in the grey long-eared. And the final one is that brown long-eared's, it's a slightly smaller bat. So there's a lot of overlap, but they have long, thin thumbs. So the way to do it is to measure the thumb length, measure the forearm length, and then take the ratio that's much higher in brown long-eared bats. And that separates them completely if anyone ever has to do it. It's about 19% in brown long-eared's, and 14 in greys and that takes account of the individual size variation in bats as well.

Steve Roe:

And why are the ears of long-eared's

Unknown:

just very briefly for those who don't know about the evolutionary arms race...Initially when the were no no mammals, insects were deaf because they didn't have to hear then in the ear seen when the bats came along. They didn't bend to develop to develop these hearing organs which aren't ears as we imagined and they can be anywhere on a pulp or on a wing or something. The moths species which have them or the noted onto the the Noctuidae geometrically arc to the n pi reality so quite a range of moth species have these hearing organs. Green lacewings have got them plus some beat beetles including some tiger beetles dung beetles. And in the tropics, mantises feel crickets and something Neptune bugs. Now what happens is that the reason longyear Bats ears are so big, it's been found that they act as an acoustic horn and they magnify sounds at low frequencies. And the best frequency that elongate bats ear can detect and magnify is 12 kilohertz, which is exactly the frequency at which a moths wings flutter. So because the moths can hear the bats coming, what these bats have done is they echolocate very, very quietly anyway. So they can actually just drop it almost to the point where they can't hear themselves. And then they just listen for the fluttering sounds. And because they're so so manoeuvrable, so easy. They can get right down in among it, they can just go in. I've even seen them walking along the ground grabbing moths, and that's why they wonder the few bats in Britain that actually can can specialise on moths and moths are good, they're juicy, they're soft, they're quite easy to catch. And importantly they fly all night so you're not restrained like a pimple Australia's by the dusk and dawn insect beaks?

Steve Roe:

And what about the mating strategies? There's this idea that long-eared bats do swarm in the autumn. But when we're doing the studies, we're finding that actually the most common species are Natterer's and yet we know that along is the second most common species. So it doesn't, the numbers don't seem to stack up.

Sue Swift:

In the 20th years monograph on longest was

Unknown:

There is some evidence that this is one of the main differences between the two species that I look, I look at the grey long-eareds first which are quite aggressive bats and they tend to meet in the autumn only and in the in the nursery roosts you tend to get one male two group of females. So it looks like what they're actually doing a classic female resource strategy, one male is guarding these females. But the great the brown long-eared bats have a different way of doing it. Because they meet all in the autumn and all winter, they mate intermittently or winter, a male couldn't guard all the females. Therefore it looks like they have a random promiscuous mating system. But it seems to be less at swarming sites and more taking place in the maternity roosts right at the end of the summer. So they do swarm but probably not in the sites where you're looking for them, which is where the Myotis bat swarm. published several new exciting research techniques have been developed, such as cheap DNA testing full spectrum detectors, radio tags, the thermal imaging stuff we've just seen in the last session. If you could have had just one of today's techniques back then which one would you choose? And why? Well, I was going to say really good radio tags for some of my early work. But we saw a brilliant talk this morning on high definition thermal imaging, I would have loved to have had that. Yeah, radio tags, I think would have been would have been fantastic. On the other hand, improvements in DNA analysis now looks as though my particular skill in faecal analysis is going to be redundant. We can simply put the droppings through a through a machine and it will tell us exactly what it ate. So the future is very bright. And we're going to find out a lot more.

Steve Roe:

And what do we know now about long-eared bats that we didn't know 20 years ago and what has surprised you most?

Unknown:

I think the most interesting and probably surprising feature is their ability to produce all these sibling species. What looked like one long-eared species in the 50s in in the whole of Europe is now about five or six because every time they do more DNA, they find that there are more sibling species and that they're specieating I think that's an amazing thing to find out. Somewhere we're going.

Steve Roe:

Sue that's been a fascinating insight. Thank you very much.

Sue Swift:

Thanks very much. I enjoyed it.

Steve Roe:

So it's the afternoon session here at the conference, and I've grabbed a few minutes with Tracy Jolliffe. Tracy, what what what is your background in rabies or medicine? What's your job at the moment?

Tracey Jolliffe:

I originally started as a veterinary nurse and I did that for quite some time and then went to university as a mature student and retrained as a microbiologist. So I've done both bacteriology and virology. And I've also done three years in the rabies research labs down in Weybridge.

Steve Roe:

So, first question, what is rabies?

Tracey Jolliffe:

Rabies is a viral infection. It's been around for a long time, we've got references going back 1000s of years to what was probably rabies infections, although it's not named as such. And viruses the difference between viruses and bacteria is that viruses are true parasites. They have to actually infect cells in order to replicate. Whereas bacteria are free living organisms and they can live and replicate on all sorts of innate objects. They don't need human or animal cells.

Steve Roe:

And what's the history of rabies in bats?

Tracey Jolliffe:

Rabies is probably been in bats for 1000s and 1000s of years. Nobody's going to be completely sure about that. In terms of bats in the UK, the first bat we had with rabies was a Daubenton's on the south coast. And that was back in the mid 80s. And first of all, we thought it was probably just a migrant, you know, it come over either assisted passage on a ship or just flowing the short distance over the channel. So we weren't too worried about it. But then a few years later, we found a juvenile Daubenton's in Lancashire, and that was when we realised that we actually had it endemic in some of our bats.

Steve Roe:

And which species have been confirmed to have it so far.

Tracey Jolliffe:

In the UK, it's primarily Daubenton's. That's where most of the cases are. And recently, we've had a few cases in serotines on the south coast. We

Steve Roe:

hear about European Bat lyssavirus type one and type two, what's the difference between type one and two?

Tracey Jolliffe:

It's really just a genetic variation. There are 18 different species of rabies virus, and they split into different groups and European backless virus one and two are both fairly closely related to classical rabies, which is genotype one.

Steve Roe:

As bat workers as we hear about having Pre Exposure vaccinations has been important, but that guidance is slightly changing with Public Health England at the moment, are gloves still the best, first and for line of defence,

Tracey Jolliffe:

absolutely. There's something called a chain of infection that all infections follow. And there have to be all these different things in place in order to one infection go from one organism to another in what we're worried about is from a back to a human. So you just have to break that chain of infection at one point. And the easiest way to not get rabies is not get bitten. So learning how to handle that correctly is very important, and wearing gloves, because it doesn't matter what your vaccines vaccination status is, if you're not going to get bitten, then you're not going to get rabies. It's as simple as that.

Steve Roe:

And why is it the bats can cope with a virus? And are there any cases of humans having Survived Rabies exposure without vaccination?

Tracey Jolliffe:

We think that that's bats are the original host for rabies. And one of the reasons is probably, although it's never been confirmed, is that bats are a very ancient group of animals. They've been around in their current form for a very long time. So we think that they've just evolved to live with the viruses, because they are renowned for carrying lots of different viruses that they cope with fine, but if they spill over into other species can cause quite serious problems.

Steve Roe:

Obviously, rabies doesn't get a great press, given the severity of the consequences of it going undetected in humans, as bat workers, there's anything that we can put to to improve the image of that's having rabies.

Tracey Jolliffe:

I think we just need to supply the facts to people. I mean, rabies is a huge problem globally. But 99% of rabies cases across the world are from dogs. So that is the huge reservoir that we need to be concerned about, from a global point of view. So, rabies in terms of bats, it's a very small percentage of one or two species in the UK. So I think we need to emphasise that it's even if you come across that species, the chance of them having rabies is still going to be very small. And just emphasise the fact that we do take precautions you know, there is an effective vaccine, and wearing gloves and correct handling. This is going to prevent people from being exposed in the first place.

Steve Roe:

Great stuff. Tracy, thank you very much. My thanks to Liz Sue and Tracy for taking time out of the conference last year to come on the show. The various links to their social media accounts are in the show notes. And the 2021 Scottish bat conference is taking place online on Saturday, the sixth of March. And bookings for that event are now open on on the BCT website and again the link is in the show notes. And if you enjoyed this episode, why not share with us what your favourite ever encounter with a long-eared bat has been by using the hashtag BatChat. That's it for this episode. But we will be back in two weeks time in the new year with the Chief Exec of the Bat Conservation Trust Kit Stoner who will be revealing what it's like to run BCT as an organisation, and will also be giving us the latest news on the status of the British bat survey, an upcoming nationwide project so don't miss it. Everyone here at the Bat Conservation Trust wishes you all the very best for the festive period, whatever you're doing this year, and we look forward to sharing more stories with you from the world of bats in the new year.